Water heater



May 22,

fW. J. MCCLURG y WATER HEATER Filed Sept. 2l, 1925 F l 5.1. 7 I

- /N VEN TOR Patented May 2,2, 192s. 6,

.UNITED STATES :PATENT oFFlcE.

WILLIAM. J'. MCCLURG, 0F PITTSBURGH, PENNSYLVANIA.

-WATER HEATER. J

Application iled September 21, '1925. Serial No. 57,807.

The invention described herein relates to improvements 1n water heaterswhich may i be commercially 'divided into two general classes. In oneclass which will betermed a storage system, a comparatively large bodyof Water is gradually heated to a high temperature. As water is drawnfrom this body its temperature will be gradually lowered and thewithdrawal of water must be stopped until water in the tank can be againheated. In the second class water is heatedas it is being drawn for use.In this latter system the water is raised from normal temperature 'tothe desired high temperature while Howing thru and necessitates theapplication of a very-high-heat.

The invention described and claimed herein has for its object. acombination of these two systems uand consists in`a gradual heating ofwater to high temperature mingling such heated water with water atnormal temperaturethereby raising the temperature of the cold water, andthen applying heat to the mingled streams while flowing to the point ofuse. The invention is hereinafter more fully described and claimed.

In the accompanying drawings forming a part of this specification Fig. 1is a sectional elevation of apparatus adapted to the practice of theinvention claimed herein; Figs. 2, `3 and 4 are detail viewsillustrating forms of check valves adapted to prevent flow of 'waterfrom the tank directly to the point of use.

In the ractiee of the invention the upper portion ci) a tank l ofconsiderable capacity is connected by a pipe 2 to a suitable supply andhas at or adjacent to its lower end an outlet 3 connected to a suitableheater. In the construction shown, the heater consists of a coil 4 and aburner 5, the supply of gas being controlled Iby a thermostat 6 operatedby and in accordance withfchanges of temperature of the water in thetank- 1.

The outlet from the coil is connected to a service pipe 7 and also to apipe 8 which preferably enters the tank at or near the top of the tankand extends down so that its outlet will be adjacent to the outlet 3from the tank. The circulating pipe 8 is provided rpreferably adjacentto its outlet end with a valve mechanism adapted to permit of a freemovement of water down through the pipe into the tankbut will preventany materia] upward ow from the tank. A valve mechanism suitable for'thepurpose is shown `to the burner.

in Figs. 1 and 2 and consists of a. :ball 9' having such a. specificgravity that it will 'normally rest on a stop l0 located below the ports11 b ut will he moved upwardly against a seat 12 1n case of an upwardflow ot' water through the pipe 8 due to the opening of a valve in theservice pipe 7. In lieu of the construction shown in Fig. 2, the checkvalve may consist of a disc l'adapted to be seated by the upward flow ofwater against the lowercnd of the pipe 8 and provided with a guide stem14 extending down through cross bars 15 in the cage 16. As the disc hasa smaller diameter than the internal diameter of the cage, Water canflow down/- wardly through the plpe 8.

In the operation of the apparatus described herein the coil will beheated by the combustion of the as causing a circulation of water fromthe lower end of the tank through the coil and through the pipe 8 intothe heater. As soon as the water in the tank has been raised to thedesired temperature, the thermostat 'will operate to close the valvecontrolling the flow of gas When a valve in the service is opened, therewill occur an upward movement of water in the pipe 8 causing a seatingof the check valve so that water must flow from the .tank through thecoil to' and through the service pipe. In the operation of the ordinaryconstruction of instantaneous water heaters, considerable time elapsesafter opening the service valve before the water is'raised to thedesired temperature and as the Water enters the coil at a temperature ofabout 70 degrees or lower, a large quantity of gas is required to heatthe water to the required temperature. In using the apparatus describedherein, water at the desired temperature will be delivered immediatelyon openin )the service valve. As. water, is drawn om the tank cold waterwill flow in thereby lowering the temperature in the tank. The loweringof the tem-l perature in the tank willA cause thejthermorangedrespectively adjacent to opposite ends of the tank, a heater connectedtothe 'outlet of the tank, a connection extending inlet' and outlet ofthe latter, means fr preventing a reverse flow of water through suchconnection, a service pipe connected to the heater, and a thermostatdisposed Within4 said tank in the regionof said discharge connection forregulating the operation of the heater to maintain a substantiallyconstant temperature of the Water in said tank.

2. vIn a Water heater the combination of a tank having inlet and outletopenings arranged respectively adjacent the top and bottom of the tank,a heater connected to the outlet of the tank, a connection extendingfrom the heater into the tank and adapted to discharge water flowingfrom the heater into the tank at a point intermediate the inlet andoutlet of the latter, means for preventing a reverse iow of Waterthrough said connection, a service pipe connected to the heater, and athermostat device disposed Within said tank for regulating the operationofthe heater to maintain a substantially constant temperature of thewater in the tank.

In testimony whereof, I have hereunto set my hand. WILLIAM J .I MGCLURG.

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